Is it possible to control where texture is applied with weight paint or similar
Masks can be used to control where you want to have cracks. It's similar to weight paint but used in the shader editor.
Create one or two grey-value images (masks) and a MixRGB (or Mix Shader). Use the image texture as Fac value for the mix node.
Depending on your shader node setup you might need a Math mode (Multiply operation) to control the color of the cracks and the base color. Alternatively, you can different materials and transparency. The mask then controls the transparency.
Example:
Default cube with cracks